CHICAGO (CBS) — Illinois Republican leaders have filed a federal lawsuit challenging the state’s new legislative district map, which was drawn up entirely by Democratic lawmakers and approved by Gov. Pat Quinn.

The move was long expected as the map pitted many sitting GOP lawmakers in new districts with each other and strengthened the power of Illinois Democrats.

“They should be ashamed of themselves. We are optimistic that the court will agree with us and will help give our residents a Fair Map that accurately reflects our population, especially our growing Latino population,” Illinois House Minority Leader Tom Cross said in a statement.

“We could see on its face that it had some problems, and the complaint lists out the specific problems that, after careful analyzation, have shown that they are in fact there,” Illinois Senate Minority Leader Christine Radogno (R-Lemont) said.

Republicans have said the map was drawn to favor Democrats, and dilutes Republican voting power and that it doesn’t give minorities the amount of voting strength required by law. They also said it is more gerrymandered than the map drawn in 2001 – thereby violating the “compactness” requirement outlined in the constitution.

The lawsuit also alleges that the map pits 25 sitting Republican state lawmakers against each other in the 2012 election, while only eight Democratic incumbents are pitted against each other.

“The redistricting plan’s pitting significantly more incumbent Republicans against one another than incumbent Democrats is a deliberate attempt to enhance Democrats’ prospects for reelection and targets Republicans to prevent their reelection,” according to the lawsuit.

Democrats controlled the entire redistricting process, as they control the House, Senate and the Governor’s office.

Gov. Pat Quinn — who is traveling in Israel — defended the map, saying in a statement that it “represents our diverse state and protects the voting rights of minorities.”

Republicans are likely to file a separate challenge over the state’s new Congressional map, which also pits incumbent Republicans against each other in an attempt to reverse the party’s gains in the U.S. House last year.